Burning a lot of wood

Newbie

Hi, I'm new here but have been picking up some good info prior to joining. Thanks for all the great ideas.

In my avatar is the concrete block smoker I made last spring. I've used for almost a year and my family loves it when I fire it up.

I believe my setup needs some tweaking to allow me to use less wood and take less work/wood to do a long cook. I

I've sealed it up with mortar, a steel lid and better sealing steal door. It used to leak smoke from all over, now 90% of the smoke is going out the chimney and about 5-10% around the door.

However, i'm still having to burn about a 16" X 4" hickory log every 10-15 min. That's too much work and wood to keep going for 6+ hours.

My theory to fix this is to restrict the amount of air into the firebox and asking for opinions on how to be more efficient with the wood use.

The firebox is 22" X 16" X 16". The connection to the smoking chamber (40 X 32 X 24) is a block turned sidewise between the firebox and chamber. This means there are two apx 7X7" holes from the firepit to the chamber. The intake is outside end of the firebox covered with four blocks that I stack to cover between stokings. The fire burns on a great with a U shaped tunnel in the dirt to outside under the "door" blocks. I don't have any much control over the amount of air.

With a larger/hotter fire burning the smoking chamber can get to about 350F, I usually keep it around 225 - 250.

The smoking chamber door took me about 5 hours and $40 in steel to make, do I have to go to that effort for a firebox door? Any plans out there on how to make one with adustable opening size?

Master of the Pit

OTBS Member

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Joined Mar 6, 2009

Restricting the air intake may be problematic, it will slow down your fire and from what you are posting it seems temperature regulation isn't a problem. You want enough incoming air for good combustion and to turn that white smoke thin and blue

Try throwing a welder's blanket or something over the smoker and firebox to help retain heat. Stone absorbs a lot of heat so you should still be cooking after the fire goes out if you are not losing heat through cracks and seems

Newbie

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Joined Feb 10, 2014

Thanks, alblancher.

So it sounds like you're saying I can use a smaller fire if I don't lose so much heat off the 1/16th steel roof. Hmm. I have some belgian and concrete block I could put over it to insulate too. Appreciate your suggestions. Will leave the firebox be for now.

Smoking Fanatic

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Joined Jan 4, 2014

Welcome.

Based on the looks of your build, it looks like you are losing a lot of smoke that is not coming from the stack. So looks like smoke (and heat) are escaping your build very easily, which makes a very inefficient burn.

I may be wrong because it is hard to tell how smoke is flowing from looking at the picture.

Either way, if your pit is losing a lot of smoke and heat, the fire will eat through more fuel to keep you at a desired cooking temperature. If you can seal off your pit better and insulate it, it will take less fuel to keep the fire burning hot inside of the pit. The idea is to have all of the heat radiating inside of the cooker and pushing out of the stack, rather than escaping through the walls of the pit.

I am by no means an expert on pit engineering, at least as much as some on this board, but that is what seems like your issue in my opinion.

Master of the Pit

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Joined May 10, 2012

The first and easiest thing you should do is pick all that wood up off the ground and stack it on top of the smoker! It will keep your wood dry and help retain some of that heat. You only got 1/16" plate up there?

That's your biggest problem! At least lay a piece of plywood or something on top of it. And if your cinder blocks are lined up , stuff some waded up newspaper down in the holes. As long as the mortar has it sealed, it should not catch fire at those temps.

Newbie

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Joined Feb 10, 2014

Thanks for the tips and ideas!

That was only the second session after mortaring and there was still a lot of moisture in the blocks and mortar, so most of that white smoke is really steam coming off the sides. the chamber is pretty well sealed, I think. So heat loss off the roof is maybe what I need to concentrate on. The outside of the blocks stays ambient temp, pretty much, so I don't think I need to fill the holes in the blocks, but that is something for later, maybe.

Yep, only 1/16th sheet metal on top. I know that's thin but I'm cheap. So I'll work on a cheap insulating scheme, too.

Smoking Fanatic

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Joined Jan 4, 2014

Yeah, what RW suggested about the top sounds correct since heat rises. You should be able to insulate it fairly inexpensively. If you can contain more of the heat within the cooker, it will take a lot less wood to stay at your desired cooking temp.

Nice looking build though! I know a guy who built a cinder block pit, but he didn't seal it off with mortar or anything so it was likely even more inefficient than your's.